An optical layered body, which comprises functional layers having various properties such as an antireflection property, an antistatic property, a hard coating property, and an antifouling property, is provided in an image display device such as a cathode-ray tube (CRT) display device, a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD), and a field emission display (FED).
The optical layered body has various functional layers formed on a transparent substrate. Accordingly, when a hard coating is formed on a transparent substrate, there has been a case where reflected light on the surface of the transparent substrate interferes with reflected light on the surface of the hard coat layer. As a result, there has been a problem that an interference fringe due to the uneven thickness of the layers appears and the external appearance of the optical layered body is damaged.
In order to prevent the appearance of such an interference fringe, a method is known in which a solvent permeable to a transparent substrate to swell or dissolve the substrate is used in a resin composition for forming a hard coat layer, when the hard coat layer is formed on the transparent substrate (Patent Documents 1 and 2). Use of the resin composition containing such a solvent substantially avoids the interface between the transparent substrate and the hard coat layer, so that an appearance of an interference fringe is prevented.
However, a higher-quality optical layered body has been wanted according to the improvement in quality of recent image display devices. Accordingly, it is demanded to more strictly inhibit the interference fringe, compared to the above method.
Patent Document 1: JP-A 2003-131007
Patent Document 2: JP-A 2003-205563